A professor of psychiatry at Harvard Medical School, Hobson sets forth a model of consciousness that posits brain and mind as an inseparable unity and, in self-help fashion, explains how to control one's ``brain-mind'' states to improve health, sleep, memory and learning ability. One fascinating implication of his theory is that dreaming and psychosis have much in common. Another is that abnormal modes like schizophrenia, depression, Alzheimer's disease and dementia result when neurochemical or physiological changes lead to a failure in one or more of our faculties-perception, emotion, orientation, memory, attention, energy. Hobson splices recent advances in cognitive neuroscience with his own dream research, episodes in the lives of his patients and his personal experiences, such as temporary amnesia due to a car accident. His exciting report holds equal interest for laypeople and scientists. (Nov.)